1. Field of the Invention
The present invention relates to an image capturing system and a method of generating image data.
2. Description of the Related Art
When an object is photographed using an image capturing unit such as a camera, there are many cases where the object is photographed using not only natural light but also light emitted from a light source such as a fluorescent lamp or LEDs. However, when the object is photographed using light emitted from the light source, there are cases where the emission light is specularly reflected on the surface of a document depending on materials thereof, which degrades the quality of an image. Thus, there are conventional image reading devices in which a light source is arranged at a position facing a direction in which specularly-reflected light reflected on the document is not incident to the image capturing unit (for example, Japanese Laid-open Patent Publication No. 7-7605 and Japanese Patent No. 3759887). In addition, there is another technique for suppressing the degradation of the quality of the image due to specular reflection on the document in which two light sources are arranged and emit light in a time divisional manner, the object is photographed using the image capturing unit at the time of emitting light from each light source, and the two images are synthesized together (for example, Japanese Laid-open Patent Publication No. 2001-268323).
However, when the document that is the object is curved, a position at which specular reflection is made on the document may be different from a position at which specular reflection is made on a flat document. Accordingly, when the position of the light source is arranged at the position at which specularly reflected light reflected on the flat document travels toward a direction other than the direction for the image capturing unit, in a case where a document to be photographed is curved, there is concern that specularly reflected light reflected on the document travels toward the image capturing unit and is incident to the image capturing unit.
In addition, since specular reflection differs depending on materials of a document, there are cases where emission light emitted from the light source is not specularly reflected on the document. In such a case, even when two light sources are arranged, there are cases where it is not necessary to cause the two light sources to emit light in the time divisional manner and to synthesize two images. Accordingly, it is very difficult to appropriately decrease the degradation of the image quality due to specularly reflected light reflected from the document regardless of the form of the document.
The present invention is contrived in consideration of the description presented above, and an object thereof is to provide an image capturing system and a method of generating image data capable of appropriately acquiring a high-quality image.
It is an object of the present invention to at least partially solve the problems in the conventional technology.
According to an aspect of the present invention, an image capturing system comprises a base unit arranged on a medium installation face on which a medium that is a reading target is installed, an arm unit extending upwardly from the base unit, a top unit extending from the arm unit so as to face the medium installation face, an image capturing unit configured to photograph the medium, a lighting disposed in the top unit and configured to irradiate the medium installation face, a lighting control unit configured to control driving of the lighting, and
a non-readable area determining unit configured to determine whether or not there is a non-readable area from which the image capturing unit is unable to read information of the medium due to reflected light of the lighting by the medium, based on an image corresponding to the medium that is acquired by performing a photographing process in a turned-on state of the lighting before image data of the medium captured by the image capturing unit is stored. When the non-readable area determining unit determines that there is the non-readable area, a lighting state of the lighting is set to be different by the lighting control unit, and the medium is photographed by the image capturing unit in states in which the lighting states are different from each other, and, among the image data generated in each photographing process, image data corresponding to the medium is generated by synthesizing areas except for an area corresponding to the non-readable area.
According to further aspect of the present invention, in a method of generating image data in an image capturing system including a base unit arranged on a medium installation face on which a medium that is a reading target is installed, an arm unit extending upwardly from the base unit, a top unit extending from the arm unit so as to face the medium installation face, an image capturing unit configured to photograph the medium, and a lighting disposed in the top unit and configured to irradiate the medium installation face, the method comprises performing a first photographing process in a turned-on state of the lighting to acquire an image corresponding to the medium, determining whether there is a non-readable area from which the image capturing unit is unable to read information of the medium due to reflected light of the lighting in the medium based on the image corresponding to the medium that is acquired in the first photographing process, setting lighting states of the lighting so that the lighting states are different from each other in a case where it is determined that there is the non-readable area in the determining step, performing second photographing process to photograph the medium in states in which the lighting states are different from each other by using the image capturing unit, generating image data corresponding to the medium by synthesizing areas except for an area corresponding to the non-readable area among image data generated in the second photographing process, and storing the image data generated in the generating step.
The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings.